It's functional, it beeps when I request a measure, etc, but the display broke, so I was wondering if someone was able to interface it to use with Arduino? It has two strips of holes to solder pins in the inside:

strip one:ESDA, ECLK, RET, VDD, GND => ESDA and ECLK are connected to an eeprom in the board

strip two (I guess this one is the one I need)GND, SDA, CLK, RET, VPP, VDD

I tried hooking SDA and CLK to i2c bus (with a bidirectional logic level converter) but it's not replying to any i2c address (tried this)

Also, the button that triggers the measure is connected between SDA pin and GND, so the scanner does cause it to "beep", but no answer is received in the bus.

Does anyone know what the VPP and RET pins might be for? maybe something has to be changed to enable the i2c bus or maybe this is not a i2c bus at all? Any help would be appreciated, I'm new to Arduino and electronics in general, and I don't have a scope to check more. What I'm almost sure is that the sensor (picture attached) is not a Melexis like one, it seems to be analog.

Thanks for the link!, I assumed at first that "Vpp" would be something related to probe, but it makes sense that the exposed port is used for programming (and not for communication), because I noticed that both SDA and CLK are used as simple inputs for the buttons (the "take a mesaure" button and the adjust one in the back).

I guess they just exposed that port for programming purposes, but not really listening to any commands as an i2c port in this current setup.

The other pair of i2c (ESDA, ECLK) linked to the eeprom and are likely to calibrate or set mode (F or C, etc), I see a lot of activity when taking a measure, even the kind of measure the meter considerate invalid (outside human range, no saving to "last measure" option).

I guess I can't use this for much then... I wasn't really interested in taking it back to live, I already replaced it, I was interested in the probe itself for a broader range of temperatures.

Thanks for the link again! If I discover something else I'll post details. A note about the "RET" pin, it's the same one in both ports, so whatever is it used for they wanted both when programming and when calibrating... not sure what it can be.

I gave up with this thermometer, but I removed the sensor shield and found a neat thermopile inside. As I'm able to get an idea of the pinout here (seems to be similar to this one), I'm probably going to give some use to it, will need to amplify and do some math, but at least I have something to play with